The present invention relates generally to earth working apparatus, and more particularly provides a uniquely adjustable earth scraper attachment connectable to the three point hitch of a farm tractor or the like to perform various earth scraping and grading functions when pulled behind the tractor.
Large scale earth scraping and grading operations, such as those used in the construction of a road or highway, are typically performed by utilizing a very large and very expensive device commonly known as a "motor grader". Commercial motor graders typically include an operator-controlled motor driven vehicle which has secured thereto a large, wheel-supported, fixed position frame. Supported beneath the frame is an earth scraping blade which is adapted to engage, scrape and grade the surface of the earth as the vehicle and its frame are slowly moved along the ground. The vertical position, and a variety of angular orientations, of the scraping blade relative to the fixed position frame are selectively adjustable by a rather sophisticated hydraulic control system by which the blade may be selectively moved relative to the fixed frame. In this manner the scraping depth of the blade, the side-to-side angle of its scraping pattern, and its front-to-rear earth scraping attack angle may be selectively and independently adjusted.
While such conventional motor graders are well suited to highway construction grading and other heavy duty earth leveling applications, their great bulk and high cost in many instances preclude their use in smaller scale domestic earth working applications such as, for example, the grading and recontouring of farm land soil.
At the other end of the motorized earth-scraping and grading spectrum are small earth scraping attachments which are connectable to farm tractors and the like. These conventional earth scraping attachments, which are connectable at a forward end portion to the tractor's three point hitch, typically comprise a wheel-supported frame to which is rigidly connected an earth scraping blade. The fixed position blade may be raised or lowered by raising or lowering the three point hitch.
While this conventional tractor attachment is suitable for a variety of relatively simple earth scraping operations, it has nowhere near the operational flexibility provided by the much larger and more expensive motor grader. Specifically, the scraping blade of the conventional tractor-drawn grading attachment can only be raised or lowered. It cannot be pivoted to vary the attack angle of the scraping blade, and it cannot be tilted to provide an angled earth scraping pattern. In short, such conventional tractor-drawn earth scraping attachments fall far short of the sophistication and operational usefulness of commercial motor graders.
It can accordingly be seen that a need exists for a relatively inexpensive earth scraping apparatus which can more closely approximate the various earth scraping and grading functions, for smaller scale domestic operations, of the commercial motor grader. It is thus an object of the present invention to provide such apparatus.